The present application relates to an elastomeric bearing system, and more particularly to a mount system therefor.
Flexbeam main rotor and tail rotor blade systems utilize resilient elastomeric bearings between a flexbeam and a surrounding torque tube. The elastomeric bearings position the torque tube relative the flexbeam to permit the blade to pitch, flap, lead, and lag.
The elastomeric bearings are typically referred to as snubber/dampers which include vertically stacked arrangements of spherical and flat elastomeric laminates. The spherical bearing “snubber” accommodates pitch change and flapping rotation while the flat layers accommodate lead/lag linear motions and some radial spanwise motion. The snubber/dampers are located between the flexbeam and the torque tube under a preload so that the elastomer laminates thereof remain in compression throughout the full range of articulation. The snubber/dampers are often mounted through an opening in the torque tube for attachment to a retainer plate which is bonded to the flexbeam.
Conventional elastomeric bearings may fail in response to a retainer plate disbond. After a retainer disbond, the elastomeric bearings are pulled outboard by a combination of centrifugal force and bearing preload along the sloped flexbeam. The outboard displacement is such that contact between the elastomeric bearing and the surrounding hardware may result in damage to the elastomeric bearing, the flexbeam and the torque tube.